Generally, a refrigerating cycle device is provided at a refrigerator, an conditioner, etc. The refrigerating cycle device includes a condenser and an evaporator. The condenser performs heat exchange with peripheral air by emitting heat outwardly, and the evaporator performs heat exchange with peripheral air by absorbing external heat. The condenser and the evaporator are called as a heat exchanger.
As the heat exchanger for an evaporator absorbs external heat, moisture is condensed on a surface of the heat exchanger for an evaporator thereby to form droplets. As the droplets are frozen, frost is generated. The frost lowers an efficiency of the heat exchanger, thereby being periodically removed by a defrosting device.
In order to enhance an efficiency of the heat exchanger, the heat exchanger is processed so as to have a super-hydrophobic characteristic thereon. Since the surface of the heat exchanger having a super-hydrophobic characteristic has a structure of a micrometer or nanometer size, a surface friction due to a fluid is decreased and thereby droplets are effectively removed.
A method for processing a surface of a heat exchanger includes a plasma enhanced chemical vapor deposition (PECVD), a plasma polymerization, polypropylene, a nano-structured carbon film, etc.
The above methods serve to change a shape of a surface of the heat exchanger through complicated chemical processes, or serve to implement a surface of the heat exchanger having a hydrophobic characteristic by changing a surface energy of a material. The above methods require expensive processes or long processing time, thereby having a difficulty in being utilized for a massive production.
Injection moldings formed of a plastic material or a product formed of a plastic material is provided with a micrometer or nanometer sized pattern thereon so as to have a super-hydrophobic characteristic or an optical characteristic. In order to form a micrometer or nanometer sized pattern on a surface of a product or injection moldings formed of a plastic material, the plastic moldings have to undergo an injection-molding process. Then, the plastic moldings undergo a post-processing such as a printing process, a stamping process or a surface machining process.
However, the post-processing requires a high cost. A hot-stamping process is widely used to form a micrometer or nanometer sized pattern. However, the hot-stamping process can be applied to form a simple pattern, but can not be applied to form a complicated pattern having a hydrophobic characteristic, etc.